1. Field of the Invention
The present invention relates to a sealing structure of an opening section in a vehicle, which is arranged to provide a seal between a front or rear door of a vehicle and a vehicle body by the use of a weather strip which is mounted on the peripheral portion of the front or rear door of the vehicle.
2. Description of the Related Art
Conventionally, a sealing structure of this type has used a door weather strip which is mounted on the periphery of a front or rear door of a vehicle to provide a seal between the door and the vehicle body. Then, as the door weather strip which is mounted on the front door, for example, there is cited the one shown in FIGS. 13 and 14. FIG. 13 is a side view of the same weather strip. FIG. 14A is a sectional view taken along line Iaxe2x80x94Ia of FIG. 13. FIG. 14B is a sectional view taken along line Ibxe2x80x94Ib of FIG. 13. And FIG. 14C is a sectional view taken along line Icxe2x80x94Ic of FIG. 13. In the weather strip of this type, its mainly substantially straight part is formed by extrusion, and its corner part small in the radius of curvature is formed by using a mold (cf. Japanese Utility Model Publication No. Hei. 1-168346, Japanese Utility Model Publication No. Hei. 2-26934, or the like). The weather strip fundamentally comprises a base section which is mounted on the periphery of a door, and a hollow sealing section which is extended from the base section, and is formed, for instance, with EPDM solid rubber or sponge rubber.
As shown in FIG. 13, a front door weather strip 100 includes a plurality (three in this example) of substantially linearly extrusion sections, i.e., a first extrusion section 101, a second extrusion section 102, and a third extrusion section 103. Then, the individual extrusion sections 101 to 103 are connected to each other at the respective ends by a plurality (three in this example) of molded sections 104. Here, the first extrusion section 101 is formed so as to correspond substantially to the upper portion of a front door not shown and substantially the upper half of the forward side portion of the front door, the second extrusion section 102 to substantially the lower half of the forward side portion of the front door, and the third extrusion section 103 to the lower portion and rearward side portion of the front door.
The reason why the molded sections 104 are provided is as follows: If the whole weather strip is formed by extrusion suffers from the following trouble: In the case where the corner is small in the radius of curvature, and it is desired to curve the extrusion section along the corner part, the corner part is deformed in such a manner that the hollow sealing section collapses; that is, a predetermined sealing force cannot be obtained. The extrusion sections are greatly different in sectional configuration from each other, the molded section is provided at the junction of the extrusion sections.
As shown in FIGS. 14A to 14C, the front door weather strip has each extrusion section 101 to 103 thereof provided with a base section 105, a hollow sealing section 106, and the back seal 107 projecting outwardly from the sealing section 106 in common. Further, although not shown in the figures, the front door weather strip also has each molded section 104 provided with the base section, the sealing section, and the back seal which are connected respectively to the base section 105, sealing section 106, the back seal 107 of the extrusion section 101 to 103 which is connected to the molded section 104.
The sealing lip 108 outwardly extended from substantially the middle of the back seal 107 of the first extrusion section 101 is formed integrally with the first extrusion section 101. However, the sealing lip 108 is not formed on the second or third extrusion section 102, 103, and is continuously gradually changed in length in the molded section 104 which connects the first and second extrusion sections 101 and 102 to each other.
When the front door is changed from an open state to a closed state, such a front door weather strip 100 is subjected to elastic deformation with the sealing section 106 in contact with the peripheral portion 110 of the opening section of the vehicle body. Thus, between the vehicle body and the front door, the inside and outside of a vehicle cabin is sealed air-tight and water-tight via the front door weather strip 100.
However, the molded section 104 has a borderline in making the sealing section thereof thinner, and the sealing section of the molded section 104 tends to become thicker than the sealing section 106 of the extrusion section 101 to 103. Thereby, the sealing section of the molded section 104 becomes large in rigidity, and the reaction force by the sealing section of the molded section 104, i.e., the force acting in the direction in which the front door is changed from the closed state to the open state becomes large relative to the door closing force upon closing the front door. Consequently, the resistance upon closing the front door becomes large, and there is a possibility of deteriorating the feeling of closing the front door. Particularly, in case a plurality of molded sections 104 are provided as in the front door weather strip shown in FIGS. 13 and 14A, the deterioration in feeling of closing the door becomes more remarkable.
The above-described weather strip 100 has the following problems: The front door weather strip needs three extrusion sections 101, 102 and 103, and three molded sections 104. Therefore, those sections 101, 102, 103 and 104 must be formed in different manufacturing steps, and accordingly the number of manufacturing steps is considerably large; that is, the manufacturing work is low in efficiency, and the manufacturing cost is large.
Further, in those front door weather strips, with the one shown in FIGS. 13 and 14A cited as an example, when the sealing section 106 and the peripheral portion 110 of the opening section 110 are brought into contact with each other in order to close the front door, the sealing section 106 of the front door weather strip 100 is arranged, for example in the mode shown dotted in FIG. 14A, to be elastically deformed with the whole thereof being inclined toward one side with respect to a center line m. Thus, a sliding friction is generated in the contact portion between the sealing section 106 and the peripheral portion 110 of the opening section of the vehicle of the vehicle body, and a more resistance comes to be generated upon closing the front door. Hence, there is a problem that the door closing force is increased upon closing the door, and also the feeling of closing the door is further deteriorated. Also, because of the two-dimensional pressure contact between the peripheral portion 110 of the opening section and the side wall portion of the hollow sealing section 106, sealing properties are deteriorated due to wear-out compression-set, durability, etc.
Further, not only in case of the front door, but also in case of the rear door, such actual circumstances have generally been common.
The invention is made by paying attention to such problems as lying in the conventional sealing structure. An object of the invention is to provide a sealing structure of the opening section in the vehicle by which the feeling of closing the front or rear door is improved, and also the movement of the sealing section is prevented against compression-set, durability, abrasion, etc., thus enabling improvement in sealing properties.
Another object of the invention is to provide a door weather strip and its manufacturing method which are designed as follows: The manufacturing work is high in efficiency, and manufacturing cost is low, and substantially the same sealing force is obtained at any point of the weather strip.
In order to attain the aforesaid object, according to one aspect of the present invention, there is provided a sealing structure of the opening section in the vehicle, which provides a seal between the vehicle body and the front or rear door by the use of the weather strip including the base section which is mounted on the peripheral portion of the front or rear door of the vehicle and the hollow sealing section which is formed integrally with the base section and is in elastically contact with the peripheral portion of the opening section of the vehicle body in the closed state of the front or rear door, the sealing structure of the opening section in the vehicle is arranged such that in the weather strip, the portion corresponding to the corner part of the upper portion on the center pillar side constituting part of the peripheral portion of the opening section of the vehicle body in the front or rear door is formed of the molded section molded by a molding method, and any other section is formed of the extrusion section formed by an extrusion method, and that in the peripheral portion of the opening section of the vehicle body, a ridge portion is provided as along at least part of the peripheral portion of the opening section, and in the closed state of the front or rear door, the sealing section is elastically deformed while being pressed and extended by the ridge portion in opposite directions away from the top portion of the ridge portion.
In this invention, since the sealing section of the weather strip is, upon closing each door, elastically deformed while being pressed and extended in opposite directions away from the top portion of the ridge portion formed on the peripheral portion of the opening section of the vehicle, a sliding friction force becomes difficult to generate between the sealing section and the peripheral portion. Consequently, the door closing force upon closing each door can be suppressed, and also the feeling can be improved. Also, since the sealing section is not largely tiltingly moved in deformation mode, but deformed in the direction of compression at the mounting position thereof, the deterioration in sealing properties accompanying the movement of the seal section can be prevented to improve sealing properties.
A sealing member formed separately from the weather strip may be mounted on at least one of the upper and side portions of the front or rear door.
Here, as shown in FIG. 14A, in the conventional weather strip 100, in some cases, the sealing lip 108 is formed in order to improve sealing properties, sound insulating properties, etc. However, in the sealing lip 108, the height thereof is relatively large, and moreover the height thereof is formed so as to be gradually changed in each longitudinal end portion. Hence, also in the variable extrusion method using a variable die, an advanced technique has been required in order to form the sealing lip 108.
In contrast, the sealing member playing the role equal to that of the sealing lip can be formed separately from the weather strip in the above invention, whereby there is no need for forming the sealing lip on the weather strip. Thus, any other section than the molded section in the weather strip, without being largely changed in sectional form, can be easily formed by the variable extrusion method using the variable die.
Further, in the closed state of the front or rear door, the amount of elastic deformation of the sealing section in the portion below the vicinity of the belt line portion of each door may be set to be smaller than that in any other portion.
The sliding frictional force caused between the sealing section and the peripheral portion of the opening section is further reduced upon closing each door. Thus, the door closing force upon closing each door can be reduced to further improve the feeling of closing the door. Further, since the sealing properties which are required of the portion below the vicinity of the belt line portion of each door are lower than those of any other portion, even if the amount of elastic deformation of the sealing section is thus reduced, no hindrance is constituted to the sealing properties.
Further, the height of the sealing section in the portion below the vicinity of the belt line portion of the front or rear door is preferably set to be lower than that in any other portion.
Still further, the projection height of the ridge portion in the peripheral portion of the opening section of the vehicle body corresponding to the portion below the vicinity of the belt line portion of the front or rear door is preferably set to be lower than that in any other portion.
The height of the sealing section or the projection height of the ridge portion on the peripheral portion of each door can be as described above, thereby reducing the amount of elastic deformation of the sealing section in the portion below the vicinity of the belt line portion.
The weather strip is formed such that the sectional form of at least one of the forward and rearward side portions thereof in the vicinity of the portion corresponding to the belt line portion of the front or rear door is gradually changed.
Further, a smooth continuation becomes available between the upper and lower portions in the vicinity of the belt line portion of the weather strip which are different in degree of requirement for sealing properties.
To achieve the forgoing object, according to another aspect of the present invention, there is provided a front door weather strip provided with a base section mounted on a periphery of a front door of a vehicle, and a hollow sealing section extended from the base section. The weather strip has an annular shape as a whole, the base section and the hollow sealing section are formed all over a periphery of the weather strip. Further, the weather strip comprises a molded section corresponding to a corner part of a rear side upper section of the front door, the mold molding being formed with a mold, and an extrusion section being formed continuous by extrusion. The extrusion section comprises: a first part corresponding to a region of from an upper section to a front side section of the front door, the first part having a seal lip; a second part corresponding to a corner part between the upper section and the front side section of the front door; a third part corresponding to the front side section; a fourth part corresponding to a corner part between the front side section and a lower section of the front door, a height of the hollow sealing section at the fourth part is larger than other parts in the weather strip; and a fifth part corresponding to the lower section and a rear side section of the front door. A base end of the sealing section on a vehicle outside at least the lower section of the fifth part is smaller in thickness than that of a part in the first part corresponding to the upper section of the front door.
Preferably, a length of the seal lip is gradually changed so as to become zero at the second part.
Further, both side walls of the hollow sealing section at the fourth part may be added to a same volume substantially uniformly thickness, so that a height of the hollow sealing section at the fourth part is larger than other parts in the weather strip.
According to still another aspect of the present invention, there is provided a method for manufacturing a front door weather strip provided with a base section mounted on a periphery of a front door of a vehicle, and a hollow sealing section extended from the base section. The weather strip has an annular shape as a whole, the base section and the hollow sealing section are formed all over a periphery of the weather strip. The method comprises the steps of: (A) continuously forming one extrusion section by extrusion, comprising the steps of: forming a first part corresponding to a region of from an upper section to a front side section of the front door, the first part having a seal lip integral with the hollow sealing section; forming a second part corresponding to a corner part between the upper section and the front side section of the front door, a length of the seal lip being gradually changed so as to become zero, and the hollow sealing section being changed to a substantially circular shape from a shape of the hollow sealing section at the first part; forming a third part corresponding to the front side section, the hollow sealing section being changed to an elliptic shape from the substantially circular shape of the hollow sealing section at the second part; forming a fourth part corresponding to a corner part between the front side section and a lower section of the front door, a height of the hollow sealing section at the fourth part is larger than other parts in the weather strip; and forming a fifth part corresponding to the lower section and a rear side section of the front door, wherein a base end of the sealing section on a vehicle outside in at least the lower section of the fifth part is smaller in thickness than that of a part in the first part corresponding to the upper section of the front door; and (B) forming a molded section corresponding to a corner part of a rear side upper section of the front door using a mold so as to connect both ends of the extrusion section, thereby manufacturing the front door weather strip.
The step (A) may be executed using an extrusion machine having a die of which an opening is variable in configuration.
According to the present invention, the front door weather strip is annular as a whole, and its base section is attached to the periphery of the front door of the vehicle. And the hollow sealing section extended from the base section seals the gap between the front door and the vehicle body.
In the invention, the weather strip is made up of one extrusion section and one molded section through which both end of the extrusion section are connected to each other. Hence, the number of manufacturing steps is considerably small.
In addition, the part of the extrusion section which corresponds to the region of from the upper section of the front door to the front side section has the seal lip which is formed integral with the sealing section, and the length of the seal lip is gradually changed at a corner part between the upper section and the front side section.
Furthermore, in the part which corresponds to the corner section between the front side section and the lower section of the front door, the hollow sealing section is larger in height than the other parts. Therefore, even if, when the weather strip is fixed to the front door, the part is bent and therefore the sealing section collapses somewhat; that is, it is deformed, the deformation is estimated in advance. That is, when the extrusion section is bent, the height of the sealing section of the part thus deformed is almost equal to the height of the other part. Accordingly, the sealing force will never be decreased.
In the part which corresponds to the upper section of the front door, in order to prevent the suction deformation of the door during the high speed driving, it is necessary to obtain a predetermined lap margin and to increase the sealing force. Therefore, the sealing section should have a predetermined thickness. On the other hand, if the sealing force is too high, the front door closing force is increased.
Therefore, the present invention has the above-described function and the following function: In the part which corresponds to the lower section of the front door, a base end of the sealing section on a vehicle outside in at least lower section of the fifth part is smaller in thickness than that of a part in the first part corresponding to the upper section of the front door. Therefore, the front door closing force is not increased so much. Hence, the above-described function is more positively obtained.
Features and advantages of the invention will be evident from the following detailed description of the preferred embodiments described in conjunction with the attached drawings.